Wednesday, January 6, 2010

Open Letters to NCWM by Rudy Kolaci, President of Totalcomp (Letter 2 of 3)

Letter Two: NTEP on load cells is not good for the scale industry.

NTEP, when applied to load cells, is a detriment to the scale industry. It will stifle innovation, new products and new companies from developing new products.

For years after NTEP was introduced load cells did not have NTEP certificates. At one point some of the larger load cell manufacturers wanted to push to have NTEP certificates for load cells thinking that the burden of getting a certificate would limit the competition. Their idea did not work. It did not stop new manufacturers from competing with them. It simply increased the cost of the load cell.

There appears to be a conflict in the NCWM procedure when load cells need NTEP certificates but scales can have an NTEP certificate and use non-NTEP load cells. I noticed on certificate 08-008 a bench and counter scale uses a non-NTEP load cell. That means that when the load cell is repaired or replaced it would be replaced with a non-NTEP load cell. It seems contradictory that a counter scale can have a non-NTEP load cell but a truck scale must have an NTEP load cell.

Innovation for load cells can be envisioned by this one example.

New load cells can be made without temperature compensation when the microprocessor used by the scale or indicator does a more efficient job.

The temperature can be sensed at the load cell with a thermister and the microprocessor will calibrate the scale including the effects of temperature changes. The result is a better and more accurate scale that costs less. The load cells can be made more efficiently and quickly without the temperature requirement. Having an NTEP certificate requires that the load cell perform to specifications when subjected to a temperature range. The innovation would not be allowed if an NTEP certificate is required for this component of a scale.

Luckily we do not need NTEP certificates for the other components.

The load cell does not need an NTEP certificate. Just as the A/D converter doesn’t have one. Just as the junction box doesn’t have one.

As well as the mounting hardware, eyebolts, potentiometers, resistors, integrated circuits, wire, capacitors, oscillators and other components used in building a scale that effect the accuracy. If any one of these items is faulty, poorly designed, improperly installed the scale will not work properly. Just as these items do not have NTEP certificates, the load cells do not need them either. The NTEP certificate for load cells should be discontinued.

I think that we want the scale industry to flourish. We need to remove the restrictions that are imposed when an NTEP certificate is required for a load cell.

Featured in the Weighing & Measurement magazine, December ‘09 issue.

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